1. Field of the Invention
The invention relates to the preservation of high moisture content grains and silages, the enhancement and direction of the silage or grain fermentation process, and to compositions useful in such processes.
2. Description of the Prior Art
The use of sulfite containing additives to preserve food by scavenging oxygen has long been known as described in various issued patents e.g., U.S. Pat. Nos. 2,799,583, Harris; 2,825,651, Loo et al; 3,169,068, Block; and 3,284,212, Tribble.
Prior art users of sodium metabisulfite for silage preservation purposes, such as is described in the above-noted Harris patent, have primarily been concerned with the removal of oxygen to inhibit spoilage based on the growth of oxygen-dependent mold or bacteria, and on the creation of an antibacterial substrate.
Harris describes a process for the preservation of silage by the addition of an alkaline metabisulfite and urea. The urea is present to control the corrosivity of the metabisulfites toward ferrous metals used in the construction of silos. The proportion of metabisulfite is said, by Harris, not to be critical and is said to vary from about 0.1 to 1.0%, by weight, or from 2-200 lbs/ton of silage. In such relatively high proportions, the metabisulfite has a strong antibacterial effect on the silage and destroys much of the natural bacteria required for desired fermentation. On the contrary, as will be described more fully below, the process and compositions of this invention produce a rapid anaerobic effect, and then, after chemical conversion of the alkali metal sulfite, bisulfite or metabisulfite to sulfate, serve to direct the fermentation.
In our prior U.S. Pat. No. 3,184,314, we have also described the preserving and controlling the fermentation of high moisture content grain silages and by the use of compositions comprising (a) an alkali or alkaline earth metal sulfate salt, and (b) an amylolytic enzyme, preferably malt diastase.
We have now found that we can provide superior, fast acting preservation of and fermentation control for various silages and stored grains, especially high moisture content grains, by use of the compositions of this invention.